OpenCloudOS-Kernel/mm
Domenico Cerasuolo 04fc781608 mm: fix zswap writeback race condition
The zswap writeback mechanism can cause a race condition resulting in
memory corruption, where a swapped out page gets swapped in with data that
was written to a different page.

The race unfolds like this:
1. a page with data A and swap offset X is stored in zswap
2. page A is removed off the LRU by zpool driver for writeback in
   zswap-shrink work, data for A is mapped by zpool driver
3. user space program faults and invalidates page entry A, offset X is
   considered free
4. kswapd stores page B at offset X in zswap (zswap could also be
   full, if so, page B would then be IOed to X, then skip step 5.)
5. entry A is replaced by B in tree->rbroot, this doesn't affect the
   local reference held by zswap-shrink work
6. zswap-shrink work writes back A at X, and frees zswap entry A
7. swapin of slot X brings A in memory instead of B

The fix:
Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW),
zswap-shrink work just checks that the local zswap_entry reference is
still the same as the one in the tree.  If it's not the same it means that
it's either been invalidated or replaced, in both cases the writeback is
aborted because the local entry contains stale data.

Reproducer:
I originally found this by running `stress` overnight to validate my work
on the zswap writeback mechanism, it manifested after hours on my test
machine.  The key to make it happen is having zswap writebacks, so
whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do
the trick.

In order to reproduce this faster on a vm, I setup a system with ~100M of
available memory and a 500M swap file, then running `stress --vm 1
--vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens
of minutes.  One can speed things up even more by swinging
/sys/module/zswap/parameters/max_pool_percent up and down between, say, 20
and 1; this makes it reproduce in tens of seconds.  It's crucial to set
`--vm-stride` to something other than 4096 otherwise `stress` won't
realize that memory has been corrupted because all pages would have the
same data.

Link: https://lkml.kernel.org/r/20230503151200.19707-1-cerasuolodomenico@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Chris Li (Google) <chrisl@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-17 15:24:33 -07:00
..
damon mm/damon/paddr: fix missing folio_sz update in damon_pa_young() 2023-05-02 17:21:49 -07:00
kasan kasan: hw_tags: avoid invalid virt_to_page() 2023-05-02 17:23:27 -07:00
kfence mm: kfence: fix false positives on big endian 2023-05-17 15:24:33 -07:00
kmsan printk: export console trace point for kcsan/kasan/kfence/kmsan 2023-04-18 16:30:11 -07:00
Kconfig - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
Kconfig.debug mm: change per-VMA lock statistics to be disabled by default 2023-05-02 17:23:28 -07:00
Makefile - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
backing-dev.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
balloon_compaction.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma.c mm: move most of core MM initialization to mm/mm_init.c 2023-04-05 19:42:52 -07:00
cma.h mm/cma: provide option to opt out from exposing pages on activation failure 2022-03-22 15:57:09 -07:00
cma_debug.c mm/cma_debug: show complete cma name in debugfs directories 2022-09-11 20:25:50 -07:00
cma_sysfs.c mm: cma: make kobj_type structure constant 2023-03-28 16:20:06 -07:00
compaction.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
debug.c mm/debug: use %pGt to display page_type in dump_page() 2023-03-28 16:20:09 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
dmapool.c dmapool: link blocks across pages 2023-05-06 10:33:38 -07:00
dmapool_test.c dmapool: add alloc/free performance test 2023-04-05 19:42:38 -07:00
early_ioremap.c mm/early_ioremap: declare early_memremap_pgprot_adjust() 2022-03-22 15:57:11 -07:00
fadvise.c mm: support POSIX_FADV_NOREUSE 2023-01-18 17:12:57 -08:00
failslab.c mm: fix unexpected changes to {failslab|fail_page_alloc}.attr 2022-11-22 18:50:44 -08:00
filemap.c filemap: Handle error return from __filemap_get_folio() 2023-05-06 10:08:59 -07:00
folio-compat.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
frontswap.c frontswap: don't call ->init if no ops are registered 2022-09-26 12:14:34 -07:00
gup.c x86-64: make access_ok() independent of LAM 2023-05-03 10:37:22 -07:00
gup_test.c mm/gup_test: free memory allocated via kvcalloc() using kvfree() 2022-12-15 16:37:48 -08:00
gup_test.h mm/gup_test: start/stop/read functionality for PIN LONGTERM test 2022-11-08 17:37:15 -08:00
highmem.c highmem: fix kmap_to_page() for kmap_local_page() addresses 2022-10-12 18:51:51 -07:00
hmm.c mm/hugetlb: make walk_hugetlb_range() safe to pmd unshare 2023-01-18 17:12:39 -08:00
huge_memory.c mm: don't check VMA write permissions if the PTE/PMD indicates write permissions 2023-04-21 14:52:03 -07:00
hugetlb.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
hugetlb_cgroup.c mm/hugetlb: increase use of folios in alloc_huge_page() 2023-02-13 15:54:27 -08:00
hugetlb_vmemmap.c mm, page_alloc: use check_pages_enabled static key to check tail pages 2023-04-18 16:29:54 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability 2022-08-08 18:06:43 -07:00
hwpoison-inject.c mm/hwpoison: add __init/__exit annotations to module init/exit funcs 2022-10-03 14:03:05 -07:00
init-mm.c IOMMU Updates for Linux 6.4 2023-04-30 13:00:38 -07:00
internal.h mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() 2023-04-21 14:52:02 -07:00
interval_tree.c mm/interval_tree: add comments to improve code readability 2021-04-30 11:20:38 -07:00
io-mapping.c mm: add a io_mapping_map_user helper 2021-04-30 11:20:39 -07:00
ioremap.c mm: ioremap: Add ioremap/iounmap_allowed() 2022-06-27 12:22:31 +01:00
khugepaged.c mm/khugepaged: fix conflicting mods to collapse_file() 2023-04-27 13:42:16 -07:00
kmemleak.c lib/stackdepot, mm: rename stack_depot_want_early_init 2023-02-16 20:43:49 -08:00
ksm.c mm/ksm: move disabling KSM from s390/gmap code to KSM code 2023-05-02 17:21:50 -07:00
list_lru.c mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe 2022-06-16 19:48:31 -07:00
maccess.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
madvise.c Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
mapping_dirty_helpers.c mm/mmu_notifier: remove unused mmu_notifier_range_update_to_read_only export 2023-02-02 22:32:54 -08:00
memblock.c mm: avoid passing 0 to __ffs() 2023-04-18 16:29:42 -07:00
memcontrol.c memcg: page_cgroup_ino() get memcg from the page's folio 2023-04-18 16:30:09 -07:00
memfd.c memfd: pass argument of memfd_fcntl as int 2023-04-18 16:30:11 -07:00
memory-failure.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
memory-tiers.c memory tier: release the new_memtier in find_create_memory_tier() 2023-02-09 16:51:40 -08:00
memory.c mm: do not increment pgfault stats when page fault handler retries 2023-04-21 14:52:04 -07:00
memory_hotplug.c mm: avoid passing 0 to __ffs() 2023-04-18 16:29:42 -07:00
mempolicy.c mm/mempolicy: correctly update prev when policy is equal on mbind 2023-05-02 17:23:27 -07:00
mempool.c mempool: do not use ksize() for poisoning 2022-11-30 15:58:41 -08:00
memremap.c mm/memremap.c: fix outdated comment in devm_memremap_pages 2023-02-09 16:51:46 -08:00
memtest.c mm/memtest: add results of early memtest to /proc/meminfo 2023-04-05 19:42:55 -07:00
migrate.c Add support for new Linear Address Masking CPU feature. This is similar 2023-04-28 09:43:49 -07:00
migrate_device.c mm: change to return bool for isolate_lru_page() 2023-02-20 12:46:17 -08:00
mincore.c mm: return an ERR_PTR from __filemap_get_folio 2023-04-05 19:42:42 -07:00
mlock.c mm: mlock: use folios_put() in mlock_folio_batch() 2023-04-18 16:29:53 -07:00
mm_init.c mm/vmemmap/devdax: fix kernel crash when probing devdax devices 2023-04-18 16:30:09 -07:00
mm_slot.h mm: introduce common struct mm_slot 2022-10-03 14:02:43 -07:00
mmap.c mm/mmap/vma_merge: always check invariants 2023-05-06 10:10:07 -07:00
mmap_lock.c mm: mmap_lock: fix disabling preemption directly 2021-07-23 17:43:28 -07:00
mmu_gather.c mm: prefer xxx_page() alloc/free functions for order-0 pages 2023-03-28 16:20:16 -07:00
mmu_notifier.c mm/mmu_notifier: remove unused mmu_notifier_range_update_to_read_only export 2023-02-02 22:32:54 -08:00
mmzone.c mm: multi-gen LRU: groundwork 2022-09-26 19:46:09 -07:00
mprotect.c mm/userfaultfd: don't consider uffd-wp bit of writable migration entries 2023-04-18 16:29:53 -07:00
mremap.c mm/mremap: write-lock VMA while remapping it to a new address range 2023-04-05 20:02:58 -07:00
msync.c mm/msync: use vma_find() instead of vma linked list 2022-09-26 19:46:25 -07:00
nommu.c mm: vmalloc: convert vread() to vread_iter() 2023-04-05 19:42:57 -07:00
oom_kill.c mm/mmu_notifier: remove unused mmu_notifier_range_update_to_read_only export 2023-02-02 22:32:54 -08:00
page-writeback.c mm,jfs: move write_one_page/folio_write_one to jfs 2023-03-28 16:20:14 -07:00
page_alloc.c - Some DAMON cleanups from Kefeng Wang 2023-05-04 13:09:43 -07:00
page_counter.c mm: page_counter: remove unneeded atomic ops for low/min 2022-09-11 20:26:01 -07:00
page_ext.c mm/page_ext: init page_ext early if there are no deferred struct pages 2023-02-02 22:33:22 -08:00
page_idle.c mm: page_idle: convert page idle to use a folio 2023-01-18 17:12:52 -08:00
page_io.c - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
page_isolation.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
page_owner.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
page_poison.c mm: page_poison: print page info when corruption is caught 2021-04-30 11:20:36 -07:00
page_reporting.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
page_reporting.h mm/page_reporting: export reporting order as module parameter 2021-06-29 10:53:47 -07:00
page_table_check.c mm/page_ext: do not allocate space for page_ext->flags if not needed 2023-02-02 22:33:11 -08:00
page_vma_mapped.c mm/hugetlb: introduce hugetlb_walk() 2023-01-18 17:12:39 -08:00
pagewalk.c mm/hugetlb: introduce hugetlb_walk() 2023-01-18 17:12:39 -08:00
percpu-internal.h mm: percpu: fix incorrect size in pcpu_obj_full_size() 2023-02-16 20:43:55 -08:00
percpu-km.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu-stats.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
percpu-vm.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu.c mm: memcontrol: rename memcg_kmem_enabled() 2023-02-16 20:43:56 -08:00
pgalloc-track.h mm: fix typos in comments 2021-05-07 00:26:35 -07:00
pgtable-generic.c mm: add PTE pointer parameter to flush_tlb_fix_spurious_fault() 2023-03-28 16:20:12 -07:00
process_vm_access.c use less confusing names for iov_iter direction initializers 2022-11-25 13:01:55 -05:00
ptdump.c mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
readahead.c readahead: convert readahead_expand() to use a folio 2023-02-02 22:33:21 -08:00
rmap.c mm,unmap: avoid flushing TLB in batch if PTE is inaccessible 2023-04-27 13:42:16 -07:00
rodata_test.c mm/rodata_test: use PAGE_ALIGNED() helper 2022-10-03 14:03:05 -07:00
secretmem.c - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
shmem.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
shrinker_debug.c mm: shrinkers: fix race condition on debugfs cleanup 2023-05-17 15:24:33 -07:00
shuffle.c mm/shuffle: convert module_param_call to module_param_cb 2022-10-03 14:03:07 -07:00
shuffle.h mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
slab.c mm: vmscan: refactor updating current->reclaim_state 2023-04-18 16:30:10 -07:00
slab.h - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
slab_common.c mm/slab: document kfree() as allowed for kmem_cache_alloc() objects 2023-03-29 10:35:41 +02:00
slub.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
sparse-vmemmap.c mm/vmemmap/devdax: fix kernel crash when probing devdax devices 2023-04-18 16:30:09 -07:00
sparse.c sparse: remove unnecessary 0 values from rc 2023-04-21 14:52:05 -07:00
swap.c mm: swap: fix performance regression on sparsetruncate-tiny 2023-04-16 10:41:24 -07:00
swap.h mm: remove the __swap_writepage return value 2023-02-02 22:33:33 -08:00
swap_cgroup.c mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled 2022-10-03 14:03:36 -07:00
swap_slots.c mm/swap: convert put_swap_page() to put_swap_folio() 2022-10-03 14:02:46 -07:00
swap_state.c mm: return an ERR_PTR from __filemap_get_folio 2023-04-05 19:42:42 -07:00
swapfile.c sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes 2023-04-16 12:31:58 -07:00
truncate.c mm: return an ERR_PTR from __filemap_get_folio 2023-04-05 19:42:42 -07:00
usercopy.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
userfaultfd.c userfaultfd: use helper function range_in_vma() 2023-04-21 14:52:02 -07:00
util.c mm: uninline kstrdup() 2023-04-08 13:45:37 -07:00
vmalloc.c mm: vmalloc: rename addr_to_vb_xarray() function 2023-04-18 16:29:48 -07:00
vmpressure.c mm/vmpressure: fix data-race with memcg->socket_pressure 2021-11-06 13:30:40 -07:00
vmscan.c mm: shrinkers: fix race condition on debugfs cleanup 2023-05-17 15:24:33 -07:00
vmstat.c mm: introduce per-VMA lock statistics 2023-04-05 20:03:01 -07:00
workingset.c mm: workingset: update description of the source file 2023-04-18 16:30:11 -07:00
z3fold.c mm: remove PageMovable export 2023-01-18 17:12:57 -08:00
zbud.c zpool: clean out dead code 2022-12-11 18:12:10 -08:00
zpool.c zpool: remove MODULE_LICENSE in non-modules 2023-04-13 13:13:54 -07:00
zsmalloc.c zsmalloc: move LRU update from zs_map_object() to zs_malloc() 2023-05-17 15:24:33 -07:00
zswap.c mm: fix zswap writeback race condition 2023-05-17 15:24:33 -07:00